What is this blue round sleeping tablet being sold in uk?

This small round blue tablet widely available and sold for around £12for 20 tabs. NO MARKINGS AT ALL. Colour comes off and stains skin/mouth/anything it touches. No box or bottle, posted loose in a bag, described as anti-anxiety/insomnia pill 10mg. When taken regularly causes serious memory loss and confusion, my daughter ended up in hospital after being found wandering streets in middle of night highly confused, she has complete amnesia re the incident. When taken it causes deep deep sleep, not even waking with painful stimuli, again daughter fell asleep infront of fire and has serious burns she didnt even stir just woke up with large blistering burns, it did not even lessen the deep sleep. What is in these tablets does anyone know? Please help as I am seriously worried about her mental health, effects of tablets (confusion) is prolonged. She is on lots of medication for a chronic illness, I dont even know if they are safe to mix with her other pills. Thank you to anyone who can help me understand this tablet.